Air Suspension - Deflating

[rmacgurn]

Originally Posted by hamh

Yup, looks the same. Except the rod in the middle was stuck not movable in my current one in the compressor, and this new replacement has the rod movable.

Now I’m trying to figure out why the one in my Amazon link looks very different, more block like or is that two parts the piston part and the air hose inlets? It’s more money too.

[hamh]

So I took the compressor out again, put in the solenoid valve as seen in the pictures below, as you can see the part is one to one the same except the original one has the middle rod stuck and I have to use a pliers to take the rod out as there is some resistance between the hole and the rod.

I swapped the solenoid valve with the aftermarket one, I quickly connects everything back and just try it under the car, but the whole compressor won't turn on at all. So I swapped the original one back, and compressor can turn on, which make me think the aftermarket solenoid valve might be a lemon. I know the rod is just a metal piece and the thing that makes it a lemon would be the main chunk of the valve, so I swap the rod from the aftermarket one to the original, and it still has a slight resistance, but I think it can move much better instead of getting stuck, put everything back on and give it a try. Magically, the compressor turned on (because of the original part), but the pressure also starts building up (thanks to the rod from the aftermarket valve).

I was so happy as I fix the compressor, but story doesn't end it. I saw both sides of my rear wheels start rising up after I starts the car, but after a minute, the right hand side wheel start lowering again while the left rear stay up. By that time it's already late and I decided to call it a day.

I think I fixed the compressor problem by making the solenoid valve movable again, but something is wrong now on the right rear side, may be something is leaking on the right hand side or may the sensor on the right side is bad?

One more thing to note, when I was observing the right hand side lowering again, I hear the compressor tried to pump pump pump and the release with a hiss sound when the right rear side lower on its own.

What do you guys think? If only one side is down now, what can be the next culprit?

[tlow98]

Airbag would be my first guess. How old are yours?

[hamh]

Originally Posted by tlow98

Airbag would be my first guess. How old are yours?

I just swapped my airbags to a pair of brand new Arnott a week ago, that was how I started my journey on finding the root cause of the problem.

[rmacgurn]

what about the listed control unit item#13 in this picture?
I don't see individual sensors for ride height.

I am starting Tuesday on mine. has been fine for 3 days now. last two times it happened was rainy wet days so I am hoping its the desiccant issue. if not the suck valve like you had as both mine deflate together.

https://1drv.ms/i/s!AozfpCQo3hMNqEsA...PQCjV?e=hluG3E

rick

[rmacgurn]

here is the pic without going to a link.

[hamh]

Originally Posted by rmacgurn

what about the listed control unit item#13 in this picture?
I don't see individual sensors for ride height.

I am starting Tuesday on mine. has been fine for 3 days now. last two times it happened was rainy wet days so I am hoping its the desiccant issue. if not the suck valve like you had as both mine deflate together.

https://1drv.ms/i/s!AozfpCQo3hMNqEsA...PQCjV?e=hluG3E

rick

I started the car this morning again and immediately found out what was wrong. The red and blue air hose connection is leaking, and I'd think it's because I take them out too many times and I basically stripped the thread on the plastic side of it. I'm going to use teflon tape as a temp fix and probably will look to replace the black block part.

[rmacgurn]

Originally Posted by hamh

I started the car this morning again and immediately found out what was wrong. The red and blue air hose connection is leaking, and I'd think it's because I take them out too many times and I basically stripped the thread on the plastic side of it. I'm going to use teflon tape as a temp fix and probably will look to replace the black block part.

that block part seems to combine the connections for air lines here but might also include teh piston assembly?
check this link,

https://www.amazon.com/gp/product/B0...HQME6C59&psc=1
I just discovered mine down now after using fine the am to go out shopping. Opened the diver door and the pump came on and car raised up but as soon as pump stopped could hear air exiting on the right side some where around the rear tire or slightly ahead. but can understand why bags if bad would only leak sometimes. if its a hose then either side since they connect at the block would allow both sides to go down I think.

let me know if that does it. but before you pulled the pump it was going down so doesn't seem that the fittings leaking were the problem before maybe just the piston thing.

[rmacgurn]

Originally Posted by hamh

I started the car this morning again and immediately found out what was wrong. The red and blue air hose connection is leaking, and I'd think it's because I take them out too many times and I basically stripped the thread on the plastic side of it. I'm going to use teflon tape as a temp fix and probably will look to replace the black block part.

for reference this is really the only other part left which controls the ride hight and bags. and not cheap..
https://www.ebay.com/itm/32575534674...Bk9SR7qHn4DHYg

[hamh]

Alright guys, I'm glad to say I finally fix the air suspension, and the last culprit was really the air output connection from the compressor as I took them out too many times. Teflon tape is what I used for this step to seal the connection.

I'm going to drive it around and will provide a summary later tonight for those who are going to tackle similar problem.

[tlow98]

Originally Posted by hamh

Alright guys, I'm glad to say I finally fix the air suspension, and the last culprit was really the air output connection from the compressor as I took them out too many times. Teflon tape is what I used for this step to seal the connection.

I'm going to drive it around and will provide a summary later tonight for those who are going to tackle similar problem.

Thanks for following up. Super helpful to everyone in the future.

[hamh]

Steps I did:
1) Change Air Suspension set to Arnott, which surprisingly the car was up for 1 to 2 days looking good and then they sagged again
2) Took the compressor out as I know it's the next thing, figure it's the desiccant beads that everyone said.
3) Since I have the compressor opened up, I figure I take a look at the solenoid valve, and found out the moving rod piece is quite stuck
4) change beads don't fix it, ordered solenoid valve and swap just the rod in to make the original valve movable again, and this fixed the compressor
5) air hose (red and blue) connection has leak after I fixed the compressor, it might be due to the fact that I took the compressor out multiple times and being rough when I try to unscrew and screw it back in
6) add some teflon tape to the connector threads, and no more leak anymore, compressor is able to pump air and raise the rear up


Conclusion:
Unless you know your air bag is bad or it has a leak, I'd say very likely it's the compressor solenoid valve being stuck. The desiccant beads is not a problem for me even though I changed mine, and I remember reading somewhere that the bead is the problem if the air suspension stay up and can't lower down.


Tips:
-Put on an eye protector or goggle when you take the under car panel off, there can be dust, sand or whatever dirt that can fall into your eyes
- when taking the compressor out from the car, it'd be easier if you have something to lift the compressor while it has been unscrewed from the car while some cable and air hose are still connected. For this I used two packages of cat paper scratcher to stack it up.
- when unscrewing the red and blue air hose from the compressor, be gentle and don't be like me shredding the threads
- when you taking the compressor apart for the desiccant beads, be super careful, during my multiple dissembles, I repeatedly pour the whole can of beads out accidentally, lucky I have whole bag of spare available,
- you have to take that cylinder of desiccant beads container out in order to access the solenoid valve, so when you do that, I'd recommend using some tape to hold the lid of the desiccant beads container, so that you won't accidentally pour them out and make a mess
- the desiccant beads container is the black plastic cylinder, not the silver metal cylinder

Tools needed:
- 10mm wrench socket and socket wrench for the most part
- 10mm traditional hand wrench for the air hose
- 1/4" socket for some screw on the under panel (might be wrong I barely remember this one)


Arnott Air suspension that I ordered:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Solenoid valve that I ordered:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[RED_Y_]

Just my .02- desiccant beads should be replaced more often so it helps with excessive moisture and valve corrosion, in your case replacing beads did not do much since valve was already stuck.

[Kzang]

Originally Posted by hamh

Steps I did:
1) Change Air Suspension set to Arnott, which surprisingly the car was up for 1 to 2 days looking good

I'm confused. If changing the air bags with the new ones kept your ride height up, why did you proceed to the compressor? Unless the suspension sagged again after 2 days then I understand.

My X5 was sitting in the garage for over 20 days untouched and driver side rear sagged all the way about 3 weeks ago and after starting the car it went back up and hasn't sagged since. I'm also reading that when the car sits untouched for a long period of time the bags deflate after a while.

[hamh]

Originally Posted by Kzang

I'm confused. If changing the air bags with the new ones kept your ride height up, why did you proceed to the compressor? Unless the suspension sagged again after 2 days then I understand.

My X5 was sitting in the garage for over 20 days untouched and driver side rear sagged all the way about 3 weeks ago and after starting the car it went back up and hasn't sagged since. I'm also reading that when the car sits untouched for a long period of time the bags deflate after a while.

Yea, the car was only up for 1 to 2 or so, and the day after, both sides sagged again, that's why I proceed to the next potential culprit, which is the compressor.

And I discovered the sagging after a 10 days trip and my car was sitting in the garage the whole time. I think my compressor was having problem in the first place, so when the air bags got deflated after a long period of time, it can't pump it back up because the valve is stuck already.

However, I can't say it's a proof that the air suspension will deflate on it's own after sitting for a long time, may be some leaking was happening in the first place already. For your case, it's odd that only one side is sagging, and this can be a sign of somewhere is slowly leaking on the driver side, I'd check the air hose input to the air bag on the driver side, and also the output from the compressor, I think the driver side is the red hose.

[hamh]

Originally Posted by RED_Y_

Just my .02- desiccant beads should be replaced more often so it helps with excessive moisture and valve corrosion, in your case replacing beads did not do much since valve was already stuck.

How often do you think it should be replaced? Taking it apart is a bitch and it potential wears off the thread of the output valve that connects to the two hose also.

[tlow98]

Originally Posted by Kzang

I'm confused. If changing the air bags with the new ones kept your ride height up, why did you proceed to the compressor? Unless the suspension sagged again after 2 days then I understand.

My X5 was sitting in the garage for over 20 days untouched and driver side rear sagged all the way about 3 weeks ago and after starting the car it went back up and hasn't sagged since. I'm also reading that when the car sits untouched for a long period of time the bags deflate after a while.

So, with new bags my car sat for two months and didn’t sag at all.

If they’re sagging at all, they’re likely on their way out. Sometimes if you park sideways on a hill or something you’ll notice they sag much faster. Then you know you’re really in borrowed time.

[kanchis]

After months of intermittent deflation, I finally got around to removing the air pump. Desiccant beads were VERY wet, so I dried them and it looks good as new. I really wanted to replace it, but couldnt find the 1-3MM beads anywhere! If someone knows a link please post it.

The next step was to check the solenoid valve. I gave it a good clean, and I tested if the valve opens with you give it power with a benchtop power supply. It did click and I can see the seal working. However, one of the posters mentioned that the metal rod should be free to move around. I had no idea that it was even supposed to do that. So I thought that it was all good.

Next, I moved to the valve block where the right and left lines connect. I didn't test them for functionality with power as visual inspection was good enough I thought. It looks really clean with no moisture. Put everything back together and put the fuse back on and started. The pump came on and it didn't last long before cutting off. I read in the forum that one person unplugged and plugged the fuse back on after replacing the pump, so I did the same. Magically the car started lifting. The pump was running strong. The car was used daily and it stayed normal for about 4 days. Then it started again! I have a strong feeling it's the solenoid but I can't find the OEM part! (WABCO 442051021) Now that I know one of you guys was successful using the Amazon part I'll try that. I was almost going to buy a new pump so I could be done with this headache. I'm going to take the pump back out tomorrow and see if I can get that metal rod moving again, and order a new one. The current delivery time is December so I'm debating If I can wait that long without a functioning car at this point. I'll sleep over it and see what direction I want to go.

[Str84ward]

Originally Posted by Mr.47

Its the airbag's its leaking around the where it creases. It takes 1-2 mins to fully fill up the air suspension (depending on how deflate it is) Unless the vehicle is in sleep mode or preserve battery mode (air pump will keep running to adjust until battery hits a low threshold) I suggest you replace them before you burn out our air compressor. I wrote a DIY replacement guide it will take 1-2 hrs to replace (CLICK HERE FOR DIY GUIDE)

Hi Mr 47 your article is awesome 👌
I am about to undertake the job but don't have ISTA D ... tried to fownlisd a copy but all links expired. Can this be done without the software 😫

[Str84ward]

Can someone point me towards ISTA D install so many moody and broken links.

[lht5059]

Originally Posted by Str84ward

Hi Mr 47 your article is awesome 👌
I am about to undertake the job but don't have ISTA D ... tried to fownlisd a copy but all links expired. Can this be done without the software 😫

This worked for me . Pumps and drives fine afterward

[kanchis]

Got the new aftermarket pump from Amazon today and I swapped it out. The new one is exactly as the OEM that came with the brackets as well. So pretty easy swap. The new pump came with a new relay (Green one in the trunk) and I swapped that as well. The ony thing I had to do was to remove the plastic valve stoppers that was installed in shipping (Valve block). When I turn the car on the pump works for a split second and it turns off. I have no idea why its doing this. Anyone got ideas?